Systems and methods for night time surveillance

Abstract

Methods and systems for surveillance are described. One described method for use in a surveillance system having a camera, comprises generating a background image of the camera's field of regard, receiving a live video image of the camera's current field of view, wherein the field of view is within the field of regard, and correlating a position of the live video image within the background image.

1 . A method for use in a surveillance system having a camera, comprising: 
 generating a background image of the camera's field of regard;    receiving a live video image of the camera's current field of view, wherein the field of view is within the field of regard; and    correlating a position of the live video image within the background image.    
     
     
         2 . The method of  claim 1 , wherein the live video image is captured by the camera at night using an infrared (IR) illuminator.  
     
     
         3 . The method of  claim 2  wherein the IR illuminator is a laser.  
     
     
         4 . The method of  claim 1 , further comprising displaying the live video image and the background image such that the position of the live video image is correlated within the background image.  
     
     
         5 . The method of  claim 4 , wherein the live video image is displayed separately from the background image and the background image includes an indicator of the position of the live video image.  
     
     
         6 . The method of  claim 4 , wherein the live video image is displayed within the background image.  
     
     
         7 . The method of  claim 6 , wherein the live video image is displayed in the center of the background image.  
     
     
         8 . The method of  claim 6 , wherein a displayed position of the live video image within the background image changes based on a change of the current field of view of the camera.  
     
     
         9 . The method of  claim 1 , wherein generating the background image comprises: 
 scanning the field of regard to capture a plurality of background sub-images; and    aligning the sub-images into a composite image.    
     
     
         10 . The method of  claim 9 , further comprising processing the sub-images by removing moving objects.  
     
     
         11 . The method of  claim 10 , wherein the composite image is processed to color correct and brightness correct the composite image.  
     
     
         12 . The method of  claim 9 , wherein scanning the field of regarding comprises scanning the field of regard a plurality of times in a plurality of different patterns.  
     
     
         13 . The method of  claim 9 , further comprising: 
 generating an IR background image; and    correlating the IR background image with the background image.    
     
     
         14 . The method of  claim 1 , wherein assembling the sub-images into a composite image comprises receiving position information and using image processing techniques.  
     
     
         15 . The method of  claim 1 , wherein correlating the position of live video image within the background image comprises receiving position information and using image processing techniques.  
     
     
         16 . A night vision surveillance system, comprising: 
 a camera having a field of regard;    an illuminator capable of producing an illumination beam;    a computer capable of generating a background image of the field of regard, receiving a live video image of a current field of view of the camera that is within the field of regard, and correlating a position of the live video image within the background image, wherein the live video image is captured by the camera using the illumination beam.    
     
     
         17 . The system of  claim 16 , wherein the illuminator is an infrared (IR) laser illuminator and the illumination beam is an IR laser illumination beam.  
     
     
         18 . The system of  claim 16 , further comprising a pan and tilt unit supporting the camera and illuminator and capable of moving the camera and illuminator, wherein the pan and tilt unit is controlled by the computer.  
     
     
         19 . The system of  claim 16 , wherein the camera and the illuminator are located in different locations.  
     
     
         20 . The system of  claim 16 , wherein a focal length of the camera and a focal length of the illuminator are capable of moving in unison.  
     
     
         21 . The system of  claim 16 , further comprising a display capable of displaying the live video image and the background image with the position of the live video image correlated within the background image.  
     
     
         22 . The system of  claim 16 , wherein the computer generates the background image by scanning the field of regard to capture a plurality of background sub-images and aligning the sub-images into a composite image.  
     
     
         23 . The system of  claim 16 , further comprising a detection system capable of providing detected targets location information to the computer.  
     
     
         24 . The system of  claim 16 , further comprising a plurality of cameras.  
     
     
         25 . A method of surveillance using at least one camera, comprising: 
 generating a background image of the camera's field of regard;    scanning the field of regard based on based on areas of interest (AOI) position information corresponding to a position of at least one AOI in the field of regard;    receiving a live video image of the camera's current field of view covering the at least one AOI, wherein the field of view is within the field of regard; and    correlating a position of the live video image within the background image.    
     
     
         26 . The method of  claim 25 , wherein the AOI position information is received from a user specifying an area of interest.  
     
     
         27 . The method of  claim 26 , wherein the AOI position information corresponds to a predetermined scan path for the camera.  
     
     
         28 . The method of  claim 27 , wherein settings on the camera are automatically changed to optimize image resolution along the scan path.  
     
     
         29 . The method of  claim 27 , wherein the predetermined scan path is managed through a user interface with direct user input.  
     
     
         30 . The method of  claim 29 , wherein the user input is at least one of an area, a path, or points of interest within the field of regard.  
     
     
         31 . The method of  claim 25 , wherein the AOI position information is received from a detection system.  
     
     
         32 . The method of  claim 25 , wherein the AOI position information is generated by image processing methods.  
     
     
         33 . The method of  claim 25 , wherein the live video image is captured by the camera at night using an infrared (IR) laser illuminator.  
     
     
         34 . The method of  claim 33 , wherein settings of the illuminator are automatically changed based on the proximity of targets in the current filed of view to the illuminator.  
     
     
         35 . The method of  claim 33 , further comprising automatically adjusting a beam divergence angle of the illuminator and the current field of view based at least in part on an average intensity of the current field of view.  
     
     
         36 . The method of  claim 33 , further comprising automatically adjusting a beam divergence angle of the illuminator and the current field of view based at least in part on content information in the current field of view.  
     
     
         37 . The method of  claim 33 , wherein the illuminator is switched off if the current field of view is illuminated by a light source.  
     
     
         38 . A night vision surveillance system, comprising: 
 a camera having a field of regard;    an infrared (IR) illuminator capable of producing an illumination beam, wherein the illuminator is separated from the camera to create a parallax; and    a computer capable of controlling the camera and the illuminator.    
     
     
         39 . The system of  claim 38 , wherein the illuminator is an IR laser illuminator and the illumination beam is an IR laser illumination beam.  
     
     
         40 . The system of  claim 38 , further comprising a pan and tilt unit supporting the camera and illuminator and capable of moving the camera and illuminator, wherein the pan and tilt unit is controlled by the computer.  
     
     
         41 . The system of  claim 38 , wherein the camera and the illuminator are located in different locations and mounted on separate pan and tilt units.  
     
     
         42 . The system of  claim 38 , wherein a focal length of the camera and a focal length of the illuminator are capable of moving in unison.  
     
     
         43 . The system of  claim 38 , further comprising a safety module capable of detecting the presence of objects too close to the illuminator and shutting off the illumination beam.  
     
     
         44 . A night vision surveillance system, comprising: 
 a camera having a field of regard;    an infrared (IR) illuminator capable of producing an illumination beam;    a computer capable of controlling the camera and the illuminator; and    a safety module capable of detecting the presence of an object too close to the illuminator and shutting off the illumination beam.    
     
     
         45 . The system of  claim 44 , wherein the safety module comprises an imaging detector capable of detecting beam reflection going back into the illumination beam and a safety processor capable of analyzing the beam reflection and shutting off the illumination beam based on the analysis.  
     
     
         46 . The system of  claim 45 , wherein the safety processor analyzes a shape of the beam reflection.  
     
     
         47 . The system of  claim 44 , wherein the safety module is capable of gradually starting up the illumination beam following shutting off the illumination beam.  
     
     
         48 . The system of  claim 47 , wherein gradually starting up the illumination beam comprises turning the illumination beam on at a reduced power and determining if an object is still present and gradually increasing power of the illumination beam if no objects are detected.